imgquant

Simple image quantizer. CPU-bound.

imgquant -h

features

• basic octree
• base, sierra lite, and floyd-steinberg dithering

plans

• clean everything up!
• flattened octree using morton order to avoid indirection for every node.
• octree with imagemagick's error pruning with YUV
• dithering: 4x4 8x8 Bayer's matrix
• out of core implementation for massive images: related issue
• parallelization of octrees (WHY ARE ALL THE PAPERS PAYWALLED??)

informal benchmarks

all using floydsteinberg dithering.

• 1381 x 1381 "Kaguya.png" | 120.1192ms (init), 86.8429ms (quant), 256 colors, depth 6
• 1381 x 1381 "Kaguya.png" | 137.909ms (init), 81.3696ms (quant), 256 colors, depth 8
• 600 x 546 "elonma.jpg" | 18.5035ms (init), 13.6052ms (quant), 256 colors, depth 6
• 600 x 546 "elonma.jpg" | 38.0389ms (init), 15.8098ms (quant), 256 colors, depth 8
• 4288 x 2848 "big_sky.jpg" | 551.3375ms (init), 529.0182ms (quant), 256 colors, depth 6
• 4288 x 2848 "big_sky.jpg" | 889.7646ms (init), 535.0434ms (quant), 256 colors, depth 8